Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A140074
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A140074 Excess over the asymptote of the number of perfect squares between cubes. +0
1
1, 1, 1, 0, 1, 0, 1, 1, 0, 1, 1, 1, 0, 1, 1, 0, 1, 0, 0, 1, 1, 1, 0, 0, 0, 1, 1, 1, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 0, 1, 1, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 1, 1, 1, 0, 0, 1, 0, 0, 1, 1, 0, 1, 1, 1, 1, 0, 0, 1, 0, 0, 1, 0, 1, 1, 1, 1, 0, 1 (list; graph; listen)
OFFSET

0,1

COMMENT

There are always at least two squares between positive consecutive cubes, starting with the perfect squares 1 and 4 between the perfect cubes 1 (included) and 8 (excluded).

The number of squares between the cube of n (included) and the cube of n+1 (excluded) is always one of the two integers bracketing 3*sqrt(n)/2.

The number a(n) in the sequence is 0 if the correct count is the lower number or 1 if the actual count is the higher number.

LINKS

G. P. Michon, A Sequence of Bits with Strange Statistics.

FORMULA

a(n) = floor(sqrt((n+1)^3-1)) - ceiling(sqrt(n^3)) + 1 - floor(1.5 sqrt(n))

EXAMPLE

The sequence starts with a(0)=1 for n=0 because there is just one perfect square (0) between the cube of 0 (included) and the cube of 1 (excluded).

This exceeds by a(0)=1 the asymptotic expression floor(1.5*sqrt(n)) for the value n=0.

CROSSREFS

Adjacent sequences: A140071 A140072 A140073 this_sequence A140075 A140076 A140077

Sequence in context: A092079 A139312 A071041 this_sequence A090174 A165556 A127243

KEYWORD

easy,nonn

AUTHOR

Gerard P. Michon (g.michon(AT)att.net), May 06 2008

page 1

Search completed in 0.002 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified November 8 20:39 EST 2009. Contains 166234 sequences.


AT&T Labs Research